# python为了将语义变得更加明确，就引入了async和await关键词用于定义原生的协程
async def downloader(url):
    return "bobby"

async def download_url(url):
    html = await downloader(url)

    return html

if __name__ == '__main__':
    coron = download_url("http://www.imooc.com")
    # next(None)
    coron.send(None)
    # coron.send()

